| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sbgoldbb |  | 
						
							| 2 |  | 2p2e4 |  | 
						
							| 3 |  | evenz |  | 
						
							| 4 | 3 | zred |  | 
						
							| 5 |  | 4lt6 |  | 
						
							| 6 |  | 4re |  | 
						
							| 7 |  | 6re |  | 
						
							| 8 |  | ltletr |  | 
						
							| 9 | 6 7 8 | mp3an12 |  | 
						
							| 10 | 5 9 | mpani |  | 
						
							| 11 | 4 10 | syl |  | 
						
							| 12 | 11 | imp |  | 
						
							| 13 | 2 12 | eqbrtrid |  | 
						
							| 14 |  | 2re |  | 
						
							| 15 | 14 | a1i |  | 
						
							| 16 | 4 | adantr |  | 
						
							| 17 | 15 15 16 | ltaddsub2d |  | 
						
							| 18 | 13 17 | mpbid |  | 
						
							| 19 |  | 2evenALTV |  | 
						
							| 20 |  | emee |  | 
						
							| 21 | 19 20 | mpan2 |  | 
						
							| 22 |  | breq2 |  | 
						
							| 23 |  | eqeq1 |  | 
						
							| 24 | 23 | 2rexbidv |  | 
						
							| 25 | 22 24 | imbi12d |  | 
						
							| 26 | 25 | rspcv |  | 
						
							| 27 |  | 2prm |  | 
						
							| 28 | 27 | a1i |  | 
						
							| 29 |  | oveq2 |  | 
						
							| 30 | 29 | eqeq2d |  | 
						
							| 31 | 30 | adantl |  | 
						
							| 32 | 3 | zcnd |  | 
						
							| 33 |  | 2cnd |  | 
						
							| 34 |  | npcan |  | 
						
							| 35 | 34 | eqcomd |  | 
						
							| 36 | 32 33 35 | syl2anc |  | 
						
							| 37 | 36 | adantr |  | 
						
							| 38 |  | simpr |  | 
						
							| 39 | 38 | oveq1d |  | 
						
							| 40 | 37 39 | eqtrd |  | 
						
							| 41 | 28 31 40 | rspcedvd |  | 
						
							| 42 | 41 | ex |  | 
						
							| 43 | 42 | reximdv |  | 
						
							| 44 | 43 | reximdv |  | 
						
							| 45 | 44 | imim2d |  | 
						
							| 46 | 26 45 | syl9r |  | 
						
							| 47 | 21 46 | mpd |  | 
						
							| 48 | 47 | adantr |  | 
						
							| 49 | 18 48 | mpid |  | 
						
							| 50 | 1 49 | syl5com |  |